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United States Patent |
5,178,780
|
Desaar
|
January 12, 1993
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Device for closing the pouring hole of a receptacle for liquid metal
Abstract
A fixed plate member, and a movable plate member is mounted against the
fixed plate member. The fixed plate member consists of a fixed metal
support plate having a plane outer metal surface and a cutout in which is
accommodated a wear part made of refractory material which is pierced with
at least one pouring orifice. The lower refractory surface of the
refractory wear part is flush with the plane outer metal surface of the
fixed metal support plate. The major portion of the rubbing surface of the
fixed plate member and contact with the movable plate member consists of
only the plane outer metal surface, while only the remaining minor portion
consists of the lower refractory surface of the wear part. The fixed metal
support plate contains a cooling chamber for holding cooling fluid which
circulates to the plane outer metal surface of the fixed metal support
plate via an orifice formed in the fixed metal support plate which also
has a groove communicating with the cooling chamber and running along a
circumference of the cutout in order to circulate the cooling fluid to
cool the wear part.
Inventors:
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Desaar; Rene (Grace-Hollogne, BE)
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Assignee:
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Recherches et Developpments Dessar (BE)
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Appl. No.:
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689255 |
Filed:
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June 12, 1991 |
PCT Filed:
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August 16, 1990
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PCT NO:
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PCT/BE90/00045
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371 Date:
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June 12, 1991
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102(e) Date:
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June 12, 1991
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PCT PUB.NO.:
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WO91/02611 |
PCT PUB. Date:
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March 7, 1991 |
Foreign Application Priority Data
Current U.S. Class: |
222/592; 222/600 |
Intern'l Class: |
B22D 041/36 |
Field of Search: |
222/600,592,591,594,597
266/236
|
References Cited
U.S. Patent Documents
311902 | Feb., 1885 | Lewis | 222/600.
|
3435884 | Apr., 1969 | Orris et al. | 222/600.
|
3685707 | Aug., 1972 | Shapland | 222/600.
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4376501 | Mar., 1983 | Hafner et al. | 222/600.
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Foreign Patent Documents |
3307193 | Sep., 1984 | DE.
| |
59-64153 | Apr., 1984 | JP.
| |
2213412 | Aug., 1989 | GB.
| |
Other References
Patent Abstacts of Japan, vol. 8, No. 170 (M-315)(1607) Dec. 1984.
Patent Abstracts of Japan, vol. 8, No. 170 (M-315) (1607), Aug. 7, 1984.
|
Primary Examiner: Kastler; S.
Attorney, Agent or Firm: Sughrue, Mion, Zinn, Macpeak & Seas
Claims
I claim:
1. In a device for closing the pouring hole of a steel-making or
metallurgical receptacle, said device comprising a fixed plate member
mounted under the pouring hole of a receptacle and a movable plate member
mounted against the fixed plate member so that the movable plate member
can be displaced relative to the fixed plate member, thereby presenting a
rubbing surface of the movable plate member against a rubbing surface of
the fixed plate member, the improvement wherein:
the fixed plate member comprises a fixed metal support plate (11) having a
plane outer metal surface (10A) and a cutout (13) in which is accommodated
a wear part (14) made of refractory material which is pierced with at
least one pouring orifice (15);
a lower refractory surface (10B) of the refractory wear part (14) is flush
with the plane outer metal surface (10A) of the fixed metal support plate
(11);
a major portion of said rubbing surfaces of the fixed plate member in
contact with the movable plate member consists of the plane outer metal
surface (10A), and only a remaining minor portion consists of the
refractory surface (10B);
the fixed metal support plate (11) has on an inner face thereof a cooling
chamber (30) which is adapted to hold cooling fluid and which communicates
with the plane outer metal surface (10A) of the fixed metal support plate
(11) via an orifice (19) formed in the fixed metal support plate (11); and
the fixed metal support plate (11) has a groove (31) communicating with
said cooling chamber (30) and running along a circumference of the cutout
(13) in order to circulate a cooling fluid for cooling the wear part (14).
2. Device according to claim 1, wherein the wear part (14) has a rim (16)
cooperating with a corresponding rim (17) on the wall of the cutout.
3. Device according to claim 1, wherein the fixed metal support plate (11)
has a lateral rim (12) containing at least one discharge channel (34) for
dust.
4. Device according to claim 1, wherein the wear part (14) has a shirt (18)
projecting from an upper face of the wear part around the pouring office
(15).
5. Device according to claim 1, wherein the fixed metal support plate (11)
is mounted in a metal mounting casing (5) fixed to the steel-making or
metallurgical receptacle.
6. Device according to claim 1, wherein the movable plate member comprises
a second metal support plate (21) pierced with at least one cutout (23) in
which is accommodated another wear part (24) made of refractory material
and through which said at least one pouring orifice (25) passes.
7. Device according to claim 6, wherein the second metal support plate (21)
is accommodated in a metal mounting casing (6) coupled to a drive
mechanism to displace the second metal support plate (21) relative to the
fixed metal support plate (11) of the fixed plate member.
Description
BACKGROUND OF THE INVENTION
The present invention relates to a device for closing the pouring hole of a
steel-making or metallurgical receptacle such as a pouring ladle, ingot
mould or continuous-casting distributor, and more particularly to a device
with a moveable plate.
A conventional pouring-hole closing device is composed essentially of a
plate made of refractory material which is accommodated in a metal casing
fixed under the bottom of the receptacle and of a moveable plate, likewise
made of refractory material, which is mounted against the fixed plate so
that it can be displaced by a translational or rotational movement in
order to close the pouring orifice of the fixed plate or to position a
pouring orifice with which it is provided opposite the pouring orifice of
the fixed plate.
When the liquid metal is poured, the stream of metal flows out through the
pouring channel of the internal nozzle, made of refractory material, of
the receptacle and passes through the pouring orifices in the elements,
made of refractory material, of the fixed plate and of the moveable plate
of the closing device. The molten metal erodes the wall of the pouring
channel and causes fairly rapid wear of the wall of the pouring orifices
in the refractory elements of the fixed and moveable plates owing to the
high temperature of the liquid metal. In addition, owing to the
temperature a decarburisation of the binder used in the manufacture of the
refractory plates occurs, which leads to a deterioration of the rubbing
surfaces of the two plates, which deterioration hinders the sliding of the
moveable refractory plate against the fixed refractory plate during each
pouring operation.
The wear of the refractory material around the pouring orifice and the
deterioration of the rubbing surfaces makes it necessary to replace the
refractory plates fairly regularly after a certain number of pouring
operations. These replacements are obviously costly in terms of refractory
material.
SUMMARY OF THE INVENTION
The object of the present invention is, on the one hand, to make these
replacements less expensive and, on the other hand, to improve the sliding
of the moveable plate against the fixed part.
This objective is achieved, in accordance with the invention, by means of a
device for closing the pouring hole of a steel-making or metallurgical
receptacle, which device is distinguished in that the fixed plate consists
of a metal support plate having a plane outer surface and exhibiting a
cutout in which is accommodated a wear part made of refractory material
which is pierced with at least one pouring orifice, the lower face of the
wear part being flush with the plane outer surface of the support plate,
so that the rubbing surface of the fixed plate in contact with a moveable
plate consists of a metal surface for the most part and of a refractory
surface of limited extent.
In a particular embodiment, the wear part has a rim cooperating with a
corresponding rim provided on the wall of the cutout.
By virtue of the invention, it is sufficient to replace the wear part alone
after a certain number of pouring operations while retaining the metal
support plate, which is considerably more convenient, quicker and less
costly than if the entire fixed plate has to be replaced, as is the case
with the conventional closing devices. The same metal support plate can
thus be used for a large number of pouring operations with the simple
replacement of the wear part.
Advantageously, the support plate has a cooling chamber on its inner face.
In addition, the metal support plate may have a groove running along the
circumference of the cutout in order to circulate a cooling fluid.
The moveable plate of the closing device according to the invention
consists of a metal support plate pierced with at least one cutout in
which is accommodated a wear part made of refractory material, through
which at least one pouring orifice passes.
By virtue of the fact that the rubbing surface of the wear part of the
moveable plate slides against a fixed surface which is for the most part
metal, the sliding is performed more easily and with less wear of the
surface of the moveable refractory wear part. And the cooling of the metal
support plate and the wear part of the fixed plate further adds to the
lessening of the deterioration of the refractory surfaces and to the
improvement of the sliding of the moveable plate against the fixed plate
in accordance with the invention.
Other aspects of the invention will become apparent on reading the
description which follows, in which the invention is explained in greater
detail with the aid of the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of an exemplary embodiment of the device
according to the invention, mounted under an ingot mould;
FIG. 2 shows, in particular, the fixed plate represented in FIG. 1;
FIG. 3 is an exploded view, in section, of the fixed and moveable plates
represented in FIG. 1;
FIG. 4 is a plan view of the fixed plate shown in FIG. 2;
FIGS. 5 and 6 are plan views of the parts constituting the fixed plate
shown in FIG. 2;
FIGS. 7 and 8 illustrate two exemplary alternative embodiments of the fixed
plate in accordance with the invention;
FIG. 9 is a top view of the moveable plate shown in FIG. 1;
FIG. 10 is a view in section along the line X--X of FIG. 9; and
FIG. 11 illustrates an exemplary alternative embodiment of the moveable
plate shown in FIG. 10.
DESCRIPTION OF PREFERRED EMBODIMENTS
With reference to FIG. 1, an exemplary embodiment of a pouring-hole closing
device according to the invention can be seen. This device is mounted
under the bottom 1 of an ingot mould having a pouring hole 2 delimited, as
is known per se, by an internal nozzle 3 made of refractory material,
constructed in the refractory lining 4 of the ingot-mould bottom. The
device for closing the pouring hole comprises a fixed plate which is fixed
under the ingot mould and a moveable plate which is mounted so as to be
able to slide against the fixed plate under the action of a drive
mechanism (not shown), known per se.
The fixed plate is described first of all with the aid of FIGS. 2 to 6.
Fixed under the ingot mould is a metal mounting casing 5 (seen partially
in FIG. 1), in which is mounted a metal support plate 11, made of
stainless steel with a polished surface, having a plane horizontal outer
face 10A. In the example illustrated, the metal part 11 is formed with a
vertical peripheral rim 12 projecting from its inner face. Formed in the
support plate 11 is a cutout 13, in which is fitted a part 14 made of
refractory material through which passes a cylindrical orifice 15 which is
placed in alignment with the pouring hole 2 of the ingot mould or other
metallurgical or steel-making receptacle. The upper face of the refractory
part 14 is intended to be constructed under the calibration washer, which
is provided at the end of the internal nozzle. The parts 11 and 14 may be
of any form in plan. The inner horizontal profile of the cutout 13 and the
outer horizontal profile of the part 14 are preferably chosen so as to
prevent the movement of the refractory part 14 in its housing. FIGS. 4, 5
and 6 illustrate an exemplary profile of the parts 11 and 14.
On the circumference of the refractory part 14 there is provided a rim 16
which is intended to cooperate with a corresponding rim 17 expediently
formed on the side wall of the cutout 13. The refractory part 14 has an
outer face 10B which is flush with the outer surface 10A of the metal
support plate 11, with a small surface compared to the total surface which
serves as rubbing surface in contact with the moveable plate, which
rubbing surface is for the most part metal.
Since it is the refractory part 14 in which is formed the pouring orifice
which is eroded as the number of pouring operations increases, it is
sufficient to replace this part 14 alone, which is considerably more
convenient, quicker and less expensive than if the entire plate 11 has to
be replaced, as is the case in the conventional constructions. The same
metal support plate 11 can thus be used for a large number of pouring
operations with the simple replacement of the refractory part 14 or wear
part, which represents a considerable saving in investment costs.
In the exemplary embodiment illustrated in FIGS. 1 to 3, the refractory
part 14 has a skirt 18 which projects from the top of the part so as to be
accommodated in a recess provided in the calibration washer of the
internal nozzle 3. This prevents the destruction of this washer during the
replacement of the refractory wear part 14. In contrast, in the known
constructions the calibration washer generally has a projecting flange on
which the conventional refractory plate fits, and this projecting flange
is frequently destroyed during the replacement of the refractory plate.
In the preferred embodiment illustrated, the metal support plate 11 is
advantageously formed with rims 12 so as to create on the inner face a
cooling chamber 30. The latter communicates with a groove 31 which runs
along the circumference of the cutout 13 and hence along the circumference
of the refractory part 14 in order to circulate a cooling fluid, for
example air. The cooling fluid may, for example, be injected via a conduit
32 connected to a fluid-supply source and the cooling fluid may be
evacuated via an evacuation orifice such as, for example, 33. In this way,
the refractory part 14 is cooled during the molten metal pouring
operations, thus reducing the deterioration of the refractory material
owing to the high temperature. At the same time, the lowering of the
temperature of the support plate 11 and of the refractory part 14 also
brings about a reduction of the temperature of the moveable plate
adjoining them. The orifice 19 formed in the support plate 11 expediently
permits the passage of cooling fluid to the outer face 10A of the support
plate 11, that is to say permits the cooling fluid to be brought to the
rubbing surface in contact with the moveable plate, thus improving the
sliding of the moveable plate against the fixed plate 11-14. Discharge
channels 34 may advantageously be provided in the lateral rim 12 of the
support plate (FIG. 4 shows three of them by way of example) for the
removal of refractory material dust, which is detached from the moveable
plate during the rubbing thereof against the fixed plate.
The metal support plate 11 and the refractory part 14 may, of course, have
various embodiments. FIGS. 1 and 2 show, by way of example, an embodiment
in which the refractory part has a projecting skirt 18. FIGS. 7 and 8
represent two other exemplary embodiments in which the refractory part 14
has no projection on its upper face. Furthermore, in these two alternative
embodiments, the outer face of the metal support plate 11 has a groove 35
in communication with a cavity 36 to facilitate the circulation of air
around the rubbing surfaces and to reduce the metal rubbing surface. The
embodiment of FIG. 8 differs again from that of FIG. 7 in that the
peripheral rim of the refractory part 14 is inverted. In the example of
FIG. 7, the refractory part 14 is placed on the side of the inner face of
the support plate 11. The replacement of the refractory wear part 14
requires the removal of the metal support plate 11, it being necessary for
these two parts to be mounted together in the mounting casing fixed under
the receptacle. With the embodiment of FIG. 8, on the other hand, the
refractory wear part 14 can be replaced without removing the metal support
plate 11.
The moveable plate of the device for closing the pouring hole may also be
constructed, in accordance with the invention, with a wear part. An
exemplary embodiment is illustrated in FIGS. 9 and 10, FIG. 9 being a top
view and FIG. 10 being a sectional view. The moveable plate comprises a
metal support plate, made of stainless steel with a polished surface for
example, having at least one cutout 23 in which is fitted a part 24 made
of refractory material, through which a pouring orifice 25 passes. In the
embodiment illustrated, the refractory part 24 is formed with two pouring
orifices 25, but the number of orifices could be other than two. The
refractory part 24 rests on rims formed inside a vertical peripheral rim
22 provided on the upper face of the metal support plate 21.
The upper face 20 of the refractory part 24 extends slightly beyond the
edge of the peripheral rim 22. This face constitutes the rubbing face
bearing against the rubbing face 10 of the fixed plate when the metal
support plate 21 is mounted in its mounting casing 6 (see FIG. 1) coupled
to a drive mechanism, known per se. When the moveable plate 21-24 is thus
put into place on a steel-making or metallurgical receptacle, one pouring
orifice 25 is in alignment with the pouring orifice 15 of the fixed plate
and with the pouring hole 2 of the receptacle. The other pouring orifice
or the other pouring orifices serve as standby reserve orifices, ready to
be placed in the operating position under the pouring hole 2 by sliding,
with a translational or rotational movement, the moveable plate against
the fixed plate. The collars 27 which surround the pouring orifices 25 on
the outer face of the moveable plate serve for the connection of an
external nozzle (not shown).
In the same way as the construction of the fixed plate in accordance with
the invention, in which the part made of refractory material is limited to
the wear part surrounding the pouring orifice, the construction of the
moveable plate as explained hereinabove has the advantage of helping to
make the replacement of the worn refractory elements considerably less
expensive than in the conventional constructions. It should also be noted
that the wear of the rubbing surface of the refractory part 24 is less
than in the conventional constructions, since this surface rubs here, for
the most part, against a metal surface 10A. In addition, this facilitates
the sliding of the hot parts against one another. To facilitate the
installation of the refractory wear part 24 in the cutouts 23 and also to
facilitate the removal of this wear part, the flanks of the cutouts 23 may
expediently be oblique, as illustrated in FIG. 11.
It is understood that the embodiments of the invention described in the
text above are examples given by way of illustration and the invention is
in no way limited to these examples. Any modification, any variation and
any equivalent arrangement must be considered to be within the scope of
the invention.
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